1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing program, an image processing method, and an image-pickup apparatus.
2. Description of the Related Art
Even in an optical system that is configured rotationally symmetrical around its optical axis, a lateral chromatic aberration that is rotationally asymmetrical may occur due to manufacturing scatterings of its lens and lens barrel. An aberrational component that is rotationally asymmetrical is referred to as a one-sided blur, and an improvement of the one-sided blur is demanded because the one-sided blur causes the image quality to degrade. One conventional method for improving the image quality detects a color shift amount of an image and executes image processing (International Publication No. WO06/093266 and U.S. Pat. No. 6,870,564). Japanese Patent Laid-Open No. (“JP”) 2010-087672 discloses a method for improving the image quality using image restoration processing.
However, no prior art has proposed a method for effectively correcting a rotationally asymmetrical curvature of field through image processing. First of all, a one-sided blur of an aberrational component that cannot be detected as a color shift, such as the one-sided blur of the curvature of field, cannot be distinguished from the image.